1. Field of the Invention
This invention relates generally to a device for transporting hazardous materials, and more particularly, to a cylinder which may be used for the transporting of hypergole materials.
2. Background
Hypergole materials such as hydrazine and dinitrogen tetroxide are commonly used in propellant applications and also in other applications such as pharmaceutical. These materials are poisonous and considered hazardous. Also, they quite commonly need to be stored and utilized under pressure. According, their transportation presents many problems.
One common use for such materials is as spacecraft fuel. Spacecraft fuel tanks for storable propellants are pressure vessels into which the fuels are loaded under pressure and are further charged with pressure to provide the driving force for the fuel to the rocket motor. The fuel tanks are normally mounted on the spacecraft and the fuel must be charged into the tanks from the delivery container while the space craft is on the launch pad or in a vehicle assembly building.
One method of shipping such hypergole materials has been by large tank trucks or railway cars. However, the delivery of the materials in such bulk quantities requires that provision be made for storage of a large quantity of the material which will not immediately be used. It is thus desirable that the material be shipped in smaller quantities.
Smaller shipments of the material have been made in 55 gallon steel drums for the eventual transfer to pressure tanks for loading into space vehicle fuel tanks and process vessels. Recognizing the hazards of the chemicals, regulatory authorities issued rule makings requiring the use of secondary containment. However, in the event of leakage or spillage, the overpack may become contaminated presenting a disposal problem. It was also discovered that these drums may have excess pressure exerted on them during transfer operations which could result premature failure.
Additionally, both the drum and tank car methods are open systems in that the container must be opened to the atmosphere for unloading. This permits potentially hazardous fumes to escape to the atmosphere and also increases the chances for spillage. As a result, when handling such "open systems" operators were required to wear protective clothing and take special precautions. As a result of the special requirements to handle the unloading of the hypergole material from these types of containers, the cost involved with the delivery and loading of the material into the space vehicle fuel tank is relatively high.
Prior art pressure tanks do not provide for features which allow them to be transported under appropriate regulations and allow the same tank to be used as part of an integrated hypergole loading and conditioning system. The prior art tanks do not have the desired light weight for ease of use nor do such tanks provide for the necessary safety when used without secondary containments.